Allowance for Doubtful Accounts - Allowance for doubtful accounts (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Jan. 01, 2020
Accounts receivable
Accounts receivable, Allowance for doubtful accounts, beginning balance	$ 39,903
One-time adjustment	74,389
Write-Offs	(4,409)
Bad Debt Expense	2,186
Accounts receivable, Allowance for doubtful accounts, ending balance	74,389
Note receivable
Notes receivable, Allowance for doubtful accounts, beginning balance	17,891
One-time adjustment	17,891
Write-Offs	0
Bad Debt Expense	(126)
Notes receivable, Allowance for doubtful accounts, ending balance	12,490
Allowance for doubtful accounts, beginning balance	52,393
One-time adjustment	92,280
Write-Offs	(4,409)
Bad Debt Expense	2,060	$ 18,470
Allowance for doubtful accounts, ending balance	92,280
Cumulative Impact from Adopting ASC 326 Guidance
Accounts receivable
One-time adjustment			$ 36,709
Note receivable
One-time adjustment			5,527
One-time adjustment			42,236
Standard note receivable
Note receivable
Notes receivable, Allowance for doubtful accounts, beginning balance	11,654
One-time adjustment	11,654
Write-Offs	0
Bad Debt Expense	(249)
Notes receivable, Allowance for doubtful accounts, ending balance	6,667
Standard note receivable | Cumulative Impact from Adopting ASC 326 Guidance
Note receivable
One-time adjustment			5,236
Elevated risk note receivable
Note receivable
Notes receivable, Allowance for doubtful accounts, beginning balance	6,237
One-time adjustment	6,237
Write-Offs	0
Bad Debt Expense	123
Notes receivable, Allowance for doubtful accounts, ending balance	$ 5,823
Elevated risk note receivable | Cumulative Impact from Adopting ASC 326 Guidance
Note receivable
One-time adjustment			$ 291